The goal of this multicenter, open-label, flexible-dose, long-term study is to further evaluate the safety and efficacy associated with the use of Sabril in epilepsy patients having partial seizures, and whose lifestyle has been adversely affected by poor seizure control and/or adverse events from currently marketed anti-epilepsy drugs (AEDs). Sabril (500 mg tablets) will be supplied in open-label bottles. The dosage will be titrated up to a maintenance dose of 2 to 3 g/day. The maximum allowable dose for the study is 6 g/day, as determined by the investigator dependent on patient response. Efficacy will be measured by the patient's response to Sabril with regard to seizure control, seizure frequency and seizure type. In addition, patient responses to selected quality-of-life questions will be measured with the QOLIE-10 (Quality of Life in Epilepsy) instrument, and patient and physician global assessment of drug therapy will be evaluated. Safety parameters will be assessed through collection of adverse events and monitoring laboratory values.